The overall objective of this project is to study the interactions between metabolism and membrane function in red blood cells. The general plan has been to perturb cell metabolism in a variety of ways and to examine the influence of the altered state on ion and water movements across the membrane. Conversely, agents which act on the membrane itself can influence metabolic controls within the cell and thus provide clues as to how the metabolic apparatus is organized. Other properties of the membrane, such as shape, stickiness, and deformability are monitored. These investigations are done in normal and congenitally abnormal human red cells and also in cells from other mammals.